Mid-'40s René Herse tandem
 

So I finally did it. I went on Ebay and put too much money where my mouth was, to get something I've always wanted.

It is a mid-'40s René Herse tandem. It is in pretty rough shape. I really don't care!!

It was listed as local pickup only on Ebay France, about 20 minutes from an old family friend's place (a cycling and tandeming friend, no less!), so he was happy to go pick it up. Here is a smattering of photos from the listing.


https://cimg0.ibsrv.net/gimg/bikefor...918d2f8958.jpg
https://cimg1.ibsrv.net/gimg/bikefor...db8992b082.jpg
https://cimg2.ibsrv.net/gimg/bikefor...a66855a2b4.jpg
https://cimg3.ibsrv.net/gimg/bikefor...f6727de17b.jpg

https://cimg5.ibsrv.net/gimg/bikefor...ab73bc2ebd.jpg
https://cimg6.ibsrv.net/gimg/bikefor...0f5b9771a0.jpg
https://cimg7.ibsrv.net/gimg/bikefor...01e32e6133.jpg


I went to France and picked it up. Took the front and rear wheels and fork and rear fender and rack off, boxed it nicely, and got it ready to go. My friend drove us all the way to the airport with the box on the roof, dodging rainstorms the whole way! It was treated pretty poorly by the airline (Norwegian CDG-BOS), but other than a slightly bent chainring, things seem fine.

https://cimg6.ibsrv.net/gimg/bikefor...ab24f04d2b.jpg
https://cimg7.ibsrv.net/gimg/bikefor...e01cafe033.jpg


It does have all the René Herse things: carbon brush for the headlight wire, Herse stem, tied-and-soldered (!) wheels with really old Maxicar hubs (so old that they say CAR-MAXI instead of the other way around), Herse cranks, and lots of custom hardware.

So over the last few weeks I've been diving into this thing. One thing became apparent pretty quickly: it's very, very old. First of all, the original owner as indicated on the stem cap, R.S. Gaulandeau, lived on Impasse Gauron in Malakoff, a suburb of Paris. Impasse Gauron no longer exists - it was bulldozed in the '50s! Secondly, it's got to be from pretty early in René Herse's production. I'm talking pre-1947. It's got some really strange bottom brackets, which I'll get into in my next post, that pre-date his aluminum-cupped SKF that I've seen on his bikes from as early as '47. Also, the serial number is 11.

https://cimg2.ibsrv.net/gimg/bikefor...2cd20ca0f1.jpg

After '46 or '47, I have been told, Herse bikes have a serial number that's composed of a year and then an ordinal number corresponding to how many frames he'd produced so far that year. So for example, if a frame was his eighth frame in 1948, he'd stamp it "48 8" or "8 48". The way I have been told, before '46 or '47, he just restarted his ordinal numbering every year from 1 and didn't include any year. I kind of find this hard to believe, because it would make things impossible to keep track of. Under this system, my # 11 could be the 11th frame of any year in the mid-'40s. Unless that was the point. I wonder if this was a wartime/immediately-postwar thing. I can imagine with rationing of metal and gas he'd rather not have anybody know how many he had made. Weird, right?

In the next few days I'll get together more stuff. I have been working hard on this, of late, and have a lot to share!

Oh damn

Sub-******g-scribed.

Oh and here are some pictures of my fantastic packing job. Thanks Norwegian...https://cimg9.ibsrv.net/gimg/bikefor...f09ea6e5b6.jpg
https://cimg0.ibsrv.net/gimg/bikefor...3c4fae619f.jpg

OK so first step of the overhaul, here's the bottom bracket removal and disassembly. These BBs are super weird, and not your typical René Herse SKF jobs either.

I had a hell of a time getting the crank bolts out. I know the standard difficulties that normally apply with French cranks: 16mm bolts and 23mm extractor threads don't leave a ton of room for a socket. I have some sockets that work on my TA and Stronglight cranks, so I thought, "no problem!" But this bike takes things to another level. None of my tools would fit, but mostly only on one side of the bolt. The hex was not centered! Now it's well known that René Herse made these bolts himself. But it looks like René probably didn't have a mill, only a lathe. The hex heads looked like they'd been done by hand, with a file! So none of my usual thin-walled sockets would fit the off-centered hex. I ended up turning a cheap socket on the lathe to make a "special tool" to get the bolts off.

I started by taking off a left crank, but the bolt wasn't really loosening. I'd gone a sixth of a turn before it occurred to me that the crank bolts were possibly reverse-threaded. Bingo!! Left side is reverse-thread. Extractor thread was TA 23mm, not Stronglight 23.35mm.

Now comes the really weird part. Look at this thing.
https://cimg4.ibsrv.net/gimg/bikefor...4ba061645a.jpg

So I surmised that those two locknuts must be like the two locknuts on a hub axle, holding cones under some preload against bearings and cups, and so I unscrewed them.
https://cimg4.ibsrv.net/gimg/bikefor...b94e8325a1.jpg

I took the dust cap off the other side. The dust caps are held in with some little wire "snap-rings". Then I tapped carefully on the BB spindle.
https://cimg6.ibsrv.net/gimg/bikefor...ec3992dba2.jpg
https://cimg4.ibsrv.net/gimg/bikefor...a63144b5d9.jpg

And then, as I predicted, it all fell out the other side. Here's the assembly, minus the cups, which are pressed into the frame and do not need to be removed. Look at those bearings!!! They are like what you'd find on the axle of a boat trailer!! And indeed, you can still get them, for pretty cheap. Trade number 30203, by my measurement. Like $25 at NAPA, or $7 on Ebay from China. I am keeping the originals, which say "TIMKEN fabriqué en France" and appear hardly worn.
https://cimg5.ibsrv.net/gimg/bikefor...ebdd877006.jpg

People tell me this is a "C.A.R." bottom bracket. As in Maxi-C.A.R. There's no branding anywhere, but they are really good quality in my estimation. They are chromed over copper plating, and the base metal is harder than a coffin nail! One has some questionable threads, which I tried to chase with a tap of appropriate pitch. I ruined the tap.

I wonder why René switched to his own design, with the very delicate aluminum reverse threading and (to my mind) inferior ball bearings. I imagine they might be better sealed. These are really barely sealed at all, if I'm being honest. The only barrier between the bearings and the outside world is the dust cap, held in with a tiny wire snap-ring.

Methinks there should be a new C&V thread for tandems.

You have such a cool bike to work on. It's rare, unique, and jusy quirky all around. Looking forward to the progress pics. Keep em coming!

Wow, first the Dujardin and now this! Considering the state of your finds you might be the most thrifty constructeur-collector around.

Fascinating the steps taken before a globalized economy to get the right hardware.

Will eagerly watch what I'm sure will be a long restoration process.

What an amazing bike, and what a fantastic story. I love the passion here, and I 100% get it. Normally I have little love for vintage tandems, but this is special.

Holy smokes!!!!!! Subscribed

Took a while to comprehend the bottom bracket assemblage. So French. Makes me think Citroen.
good employment of tapered roller bearings.
the local collection only is what probably made this tolerable in price- I would think Alexander March would have been your bidding competition.
i am assuming 650b tires... with those eyeballing the frame sizes is difficult
it will look terrific when done.

Downright incredible. Perhaps we will see this in person next October at French Fender Day??

Wonderful bike with all the special bits, and seems in pretty solid condition. I believe Herse switched to the forged brake calipers like yours in about 1946. IIRC the date didn't appear in the serial number until about 1950. A few years back I restored a 1946 Herse Competition and it was a challenge. Your bottom bracket is a lot like one on a late-40s Bianco 650B frame I had a few years ago. I believe there should be some sort of soft fibre washers to help with the sealing - see photo.
https://cimg5.ibsrv.net/gimg/bikefor...a6434836c2.jpg

Finally, a unicorn that's not in your collection!

;)

FFD 2020 is shaping up to be a must-see event...

Chainring design
 

I need new chainrings. All four are pretty worn-out, in my estimation!

Classic René Herse cranks are a little different from the ones Jan Heine sells now. These may have been among the very very first, in fact! While the 70mm bolt circle was retained throughout the years, the bolt size changed as well as the interface between the crank and the ring. Now, I had thought that Jan Heine sold replacement classic René Herse chainring "blanks" on his website, that could be filed or drilled to fit the various iterations of classic Herse cranks. He does, but not the big ring. :(

So I will have to make them myself. Simple decision is what metal to use. 7075-t6 is the premium stuff - much harder than 6061, and @jonwvara who makes triplizers happily confirmed he used it as well. Thanks Jon :)

Next is how to make them. First, the big ring, which is a 48t. I like 48. It is divisible by 3 and 2, several times over, so geometry can reference the teeth tips and achieve a lot of symmetry :)

There are well-defined engineering formulae for sprocket teeth. These formulae take three variables: chain pitch; roller diameter; and number of teeth, and use geometry to create the sprocket profile. Interestingly, only one CAD software I have access to had a macro that implemented the formula for me. I grabbed a tooth profile from there and imported it into Autodesk Fusion 360.

From here, I had to decide how to geometrically define those beautiful René Herse chainring curves. This is challenging.

Some of you may know I have some mixed feelings about Jan Heine taking over the Herse brand. I didn't really understand why I felt this way until I started really looking at the chainrings he designed. You see, the way you approach designing a chainring is a bit of a Rorschach test on your cycling philosophy. I'll explain.

Jan's ring looks like this:
https://cimg3.ibsrv.net/gimg/bikefor...c6074254eb.jpg
The circular cutouts are perfectly concentric, making structurally-sound limbs of non-varying thickness to carry the load of pedaling from the spider to the teeth. It's very pragmatic. Very German.

And that's not how René Herse did it - at least in his early days, according to the google images I've found, plus my own ring.

As my friend and Cycles René Hubris co-founder Kevin put it, "René Herse managed to be both pragmatic and whimsical." His ring looks really art nouveau. Like this:
https://cimg3.ibsrv.net/gimg/bikefor...96f4844451.png

It's subtle, as most tasteful things are.

So I am a biologist, and I thought about how the chainring looks kinda art nouveau. I have no knowledge of art nouveau, but of course I thought about how a lot of those curves must have come from biology. The cast iron vines around the Métro entrance, for example (really the only example of art nouveau I can come up with). So drawing from my love of molluscs, which have really nice, platonic, well-defined geometry, I drew this in Fusion 360:
https://cimg2.ibsrv.net/gimg/bikefor...483b5a99d0.png

Every circle is referenced to be tangent to or bisected by either some other circle (inner or total or bolt circle) or one of the six lines radiating outward from the center to make a hexagon, on three of which the bolt circle sits. Make some nice fillets and cut out the superfluous geometry and you get this.
https://cimg7.ibsrv.net/gimg/bikefor...6e7290311c.png

It is close, but no cigar. Even with seashell-inspired geometry, I'm still not as good as RH. Kevin says, "better than Jan, but still not whimsical enough."

So Kevin, who writes image processing software, took the chainring away from me and brute-forced things. He put it in an expensive flatbed scanner and he wrote a simple edge-finding algorithm to process it, and now we have this.
https://cimg6.ibsrv.net/gimg/bikefor...b1b33476e5.jpg

This is a raster file, but I think I can just put it into a vectorizing program such as Adobe Illustrator, and I'll have it! Then I'll delete the teeth, which are of course a scan of the worn ones, and overlay teeth from my sprocket-maker macro. Then the plan is to waterjet cut the ring and thin/bevel the teeth with a lathe and hand polish/file to round off the edges as the original was done.

The interesting thing about all this is we still have no idea how the original René Herse curve is geometrically defined. Kevin bets it is from a set of French curve templates, or an Euler spiral. It's interesting food for thought. It will come to one of us while in the shower, and will quickly be forgotten, before it can be posted, of course.

All this Rorschach test talk makes me wonder what Grant/Rivendell's interpretation of the chainring design would be. :lol:

Well, this cost an order of magnitude more than the Dujardin... Still cheap for a Herse. :lol:
I've been thinking a lot about the globalization angle. It's an interesting paradigm shift, but weirdly in the end I make a lot of my own screws on the lathe and mill, just because it's instant gratification, or the "only handle it once" principle.
Yeah, the plan is to ride it in the coming spring.

I certainly will, as long as my potatophone has storage space for all the pictures!!

I love old Citroëns. When I lived in France, I joined a 2CV club. Good fun with a lot of quirky old men and machines. Not unlike the cycling groups I'm in today...
The guy (that I know of) who might have otherwise bought it was Chris Gonzalez. I don't know about Alexander March. Chris had a family member in Paris, but luckily this guy was out of town at the time I bought it. He and I talked a little at French Fender Day and he has been a great source of information. He didn't seem at all unhappy not to have it, but he does have several others. :lol:
The wheel size is 650b, yes. Sorry I forgot to put that! The frame is 60cm (center-top) in front and 56cm (center-top) in back.

Yes. If all goes well, I will be there with three tandems: this, my Colin Laing, and my Jack Taylor. :)

That's an interesting look at the Herse early chainring geometry. I believe the shape evolved slightly over the late 40s, with yours being the early style with the spider arms narrowing toward the center. My 1946 has this style as well. Here are some photos of late-40s cranks from Alex March's site, showing a shape that is more like the Compass one. I have a NOS 45t Herse ring that is also this style. As elegant as the early style looks, I'm guessing that Herse may have decided to widen the inner part of the spider arms to better resist bending.

I like your drawing of the Herse chainring, but you should work in metric units as Herse did! When I was making replicas of the early Speedy brake calipers, I found that Herse always used whole mm for all circular dimensions. Aside from that, he certainly had a great feel for what worked mechanically, as well as what looked elegant.

https://cimg5.ibsrv.net/gimg/bikefor...5610e5d80c.jpg
https://cimg2.ibsrv.net/gimg/bikefor...18bbeebb68.jpg

There is a sync Real Herse chainring and RH crank on french ebay right now...

Jan's "reissue" cranks are in the style of but quite different. The radius at the chainring bolts is the most obvious difference. Not sure of the dimensions enough to know if his could be filed or machined back to work.
The fastener type may also be different.

RH crank bolts have always been a challenge even way back, grinding or machining a 6 point socket was the order of the day.

All this is possible to create, just dollars. I would look up Jim Merz, he has the knowledge and machines. Has made chainrings in the past.

Yes, those "new" chainrings are not going to work. The True Herse rings are "off" here and there, not in a bad way, but bit of trick programming to get a CNC to recreate.

This makes me think of the Bugatti moped motors...

https://www.bugattirevue.com/revue29/t72.htm

Neat to see the BB on some other bike. I have seen it on at least one other Herse, from '46, and on some other marque too. Good to know about the fiber washers. I should be able to make something out of felt.

The Herse tandem that Jan Heine toured on in BQ 62 is supposedly from 1947, but it has the newer Herse/SKF bottom bracket. So *maybe* mine is from '46? Another early thing is the lack of bracing on the left side of the rear triangle to reinforce the frame against pulling from the drum brake reaction arm.

At work I have access to all the machine tools and softwares I need to make a go at this restoration, so I think I'll be OK. At least I don't have to make up new springs for the brakes and such! The big challenge will be properly machining a replacement stoker stem (one is missing), and finding someone to do the chrome plating (Massachusetts is really terrible for this sort of thing).

Yes, I had to make my own springs. To my surprise, it was actually quite doable in a home workshop.
https://cimg0.ibsrv.net/gimg/bikefor...faf5754aaa.jpg
https://cimg2.ibsrv.net/gimg/bikefor...8ad538c7fd.jpg

It's very interesting to look at all this, for sure. A neat opportunity to really learn something, firsthand. Industrial archaeology, if you will. :)

That drawing was a bit of a mongrel/first attempt. Fear not! I did notice round numbers of millimeters coming up an awful lot as well. The specs written on that drawing are mostly rounded up or down to nearest inch only because that's the way Fusion 360 likes to display things, and I had the units set to inches because of the teeth being defined in inches because the chain is defined in inches. Again, a bit of a mongrel. The scan plus some line smoothing is probably going to work. I've been laser-cutting prototypes out of cardboard and acrylic to see how they fit and how they line up, so there's still a ways to go.

You are the one whose restoration featured in Bicycle Quarterly, right?

What a cool thread. Just wow.

Galli made a very similar tapered roller BB:
VeloBase.com - Component: Galli Criterium (roller bearing)
http://velobase.com/CompImages/Botto...D4346BFCA.jpeg

Yes, Jan was a huge help in the restoration process, providing advice and answering dozens of questions. At first it was a challenge to even deduce how my bike had originally been configured, as all the braze-ons had been removed. Jan lent me an intact early Herse frame and Speedy caliper for replication purposes. In return he asked me to write a short article for the journal, which I was more than happy to do!

Damn. This is getting more interesting with every post!

Contact Brian Chapman or Peter Weigle to find out which chrome plater they use. Once they know you're working on your tandem Herse, I'd bet they'd let you slip in some bits on one of their runs.

Jamie Swan is another good contact, you probably met him at FFD last year. He's in Long Island.

So cool.